


shining like a fiery beacon

by fyrefalcon



Series: fyrefalcon's setleth one-shots [1]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Crack Treated Seriously, Cunnilingus, Dare, Desk Sex, F/M, Light Dom/sub, Masturbation, Plot What Plot/Porn Without Plot, Porn with Feelings, Power Dynamics, Punishment, Sneaking Around, Spanking, Top Seteth, Vaginal Sex
Language: English
Status: Completed
Published: 2020-06-16
Updated: 2020-06-16
Packaged: 2021-03-04 06:35:29
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 1
Words: 5,858
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24749230
Author URL: https://archiveofourown.org/users/fyrefalcon/pseuds/fyrefalcon
Summary: Bylethknewthis was a bad idea.
Relationships: My Unit | Byleth & Seteth, My Unit | Byleth/Seteth
Series: fyrefalcon's setleth one-shots [1]
Series URL: https://archiveofourown.org/series/1789675
Comments: 13
Kudos: 148
Collections: Desk After Dark





	shining like a fiery beacon

**Author's Note:**

> I have no excuse for writing almost 6k words of crack seteth's desk challenge fic instead of literally anything else I've been working on, but...uh here it is anyway. 
> 
> re: the non-con tag: I tagged it like this for two reasons: (1) seteth spanks byleth without asking her if it's okay first, and (2) while byleth is explicitly on board with this encounter, there's some locking of doors and no consent conversation. 
> 
> i don't want anyone to be surprised, especially because I know a lot of y'all like (a) soft bottom seteth and (b) respects women juice 100% of the time under all circumstances seteth and...well...in this case you get neither! fair warning!

Manuela leaned across the table they’d set up in Byleth’s small room and poured another shot of whiskey into Byleth’s tea cup, chuckling. “Here, let me warm you up.” 

Despite the late hour, the sky outside the window was still light. The days were long with summer, and Byleth supposed they’d been drinking together for a couple of hours now, trying to take the edge off of a particularly stressful week. 

Byleth raised her eyebrows at her friend. “Truly, Manuela, you don’t think it’s warm enough?” It was the first week of Verdant Rain Moon, and the heat was oppressive, even at the elevation of Garreg Mach. 

Nonetheless, Byleth poured lukewarm bergamot tea into both her and Manuela’s cups, topping off the whiskey, and then took a sip of the bracing concoction—which, she had to admit, wasn’t actually half bad. 

“Gotta do _something_ to spice this place up,” Manuela lamented. “It’s too hot, and I’m too bored.” 

Byleth leaned back in her chair. “That reminds me. I overheard Claude and Hilda plotting. Apparently this month, they’ve decided to entertain themselves by challenging each other to sneak into Seteth’s office and use his desk for…unconventional purposes.” Byleth frowned. “Whatever that means.” 

Manuela’s mouth formed a pretty little O before she broke into her signature laugh. “Oh, the lordlings must be bored too. This summer can just…get fucked.” She leaned in, conspiratorially. “Does he know?”

Byleth shook her head. “I don’t think so. I suspect if he did know that we would hear about it.” 

Manuela nodded. “Have you had any luck with that?”

“With Seteth?”

“Yeah.”

Byleth shook her head. “No. Honestly, I think he hates me.” 

“I don’t know why you’re interested, to tell you the truth. He seems like he’d be a total bore in bed. Although…” Manuela cocked her head, thinking, “he _is_ handsome, even if he’s totally uptight.”

Byleth shrugged. There was something about the man’s demeanor that just made her ache to get under his skin. Plus—he noticed things, and loved his sister. And she liked that. Even if he was harsh sometimes. 

“Not that he’d ever have me.” She rolled her eyes, and then smiled in a way that made Byleth suspicious. “We should join them. The students, I mean.”

“You want to sneak into Seteth’s office with me to use his desk for an unconventional purpose?” Manuela’s schemes were grandiose enough to rival Claude’s, without a quarter of the plausibility. Reluctantly, she asked, “What did you have in mind?”

Manuela laughed. “What unconventional purpose is there besides sex?”

“You want to have sex with me on Seteth’s desk?” Byleth had to admit that her friend was attractive, but Manuela had made it clear since day one that she was committed to masculine attention. “This is a…surprise.”

Manuela laughed again. “Not what I meant!” She winked at Byleth. “Haven’t had quite enough whiskey for _that_ kind of adventure—although you’re quite pretty—and I’m not quite so desperate to give up on men just yet.” She considered. “Maybe we could go separately. You go tonight, and I’ll go tomorrow night. We rub one out on his desk—and if either of us gets caught or skips out, they’re up for the next bottle.” 

She picked the half empty bottle of whiskey from the table and shook it at Byleth enticingly.

Byleth sighed and shrugged. This was a bad idea, but it would take her mind off of the spectacularly strange year she’d been having…and encourage her to think instead about the stoic priest-man and all the different ways she'd like to make him come undone. “Why not. I’m in.”

She raised her teacup and Manuela clinked the rim, looking saucy. “It’s a deal.” 

*

Much later that night, Byleth stepped onto the second floor and paused, listening. The stained glass was illuminated from behind, kaleidoscopic with the light of the moon, but there was no flicker of firelight from candles or otherwise. 

Surely it was late enough that even Cyril would be in bed. 

Tentative, she took a step onto the plush carpet of the hallway, and then another. She knew—she _knew—_ she shouldn’t be here. Ruefully, she noticed that the whiskey had worn off. She couldn’t even blame her behavior on the alcohol. 

Maybe the man had been right after all. She really had no business being a professor. But who else would they have chosen to lead her class? Jeritza? 

Seteth had just told her that her role—no, her _duty_ —was to guide her students down the path of righteousness. And she tried to do her best, most days. But clearly that message hadn’t _truly_ sunk in, because Manuela hadn’t even had to work very hard to get her to agree to bringing herself off on the man’s desk. 

Why had she agreed to this? She wasn’t even bored. But she knew the answer. It was Seteth, truly. _Goddess_ , she was hot for him. It was clearly addling her brain.

Especially when he was pissed at her, like he was now—some fresh hell about Rhea giving her the glowing sword she’d found in the coffin far beneath the monastery. Good thing she’d left it in her room; it would have lit up the hallway like a beacon and broadcast her location to half the monastery besides. 

There was something deliciously disobedient about using his personal space like this, and Byleth knew this night would give her an amount of tolerance for his insulting treatment of her that it would be worth it in mental ammunition alone. 

She could only take so much of his attitude before she fought him. Or fucked him. She considered. Maybe both.

She shook her head against her own thinking. She suspected that Seteth would pledge himself to celibacy before he’d willingly fuck her, especially after all the trouble she put him through. 

This would have to do.

She crept into the shadow of the wall, edging along it until she came to Seteth’s office door. She reached out, praying the knob wouldn’t squeak, and turned it slowly, listening for the latch clearing the door. 

In one fluid motion, she exhaled and slipped inside, closing the door silently behind her. She spun the lock, inhaling again once she heard its satisfying click echo in the darkness. 

Alone in his office, she felt dwarfed by the silence of the well-appointed room. 

The moonlight streamed in from the window behind his desk, and she looked around, taking in the little cluster of chairs on the corner—did Seteth entertain? She couldn’t ever remember anyone besides Flayn gathering in his office, which made the chairs feel sort of…lonely. 

For the first time, she noticed the beautifully done tapestry of…a dragon? on the wall among the bookshelves. _Strange,_ she thought. _I wouldn’t have thought Seteth one for such fanciful art._

The plush carpet was the same as in her father’s office, but that’s where the similarities ended. There were so many different facets of Seteth himself reflected throughout the room that she found herself inspecting everything. His room felt oddly confessional, in a way that betrayed his buttoned-up nature.

In one corner, antique swords stood at the ready, perfectly polished. She hefted one into her hand, swinging it deftly through the air, feeling it hum. Well-balanced, and sharp enough for the field besides. 

Of course even Seteth’s aesthetic weapon collection was in immaculate fighting condition. 

She crossed the room, looking at the wall where his hand-drawn schematics had been pinned, one on top of another. She hadn’t realized that his work involved armaments—perhaps she could ask him to teach a seminar on this. 

She knew Ignatz, at the very least, would be interested in the marriage of building defenses and architecture that Seteth seemed to be exploring here. 

Finally, she approached his desk, noticing the chair was just slightly askew, and she wondered for a moment if she’d actually interrupted some other ill-advised foray into his office with her own presence. 

Peeking beneath the desk and finding nothing but negative space, she breathed a sigh of relief at the fact that she was well and truly alone. 

Seteth had left the center of his desk clear, save a single book that had been opened to a diagram of the human body. The administrative paperwork had been stacked carefully to one side; on top of that was another stack of paper with his perfect, thin writing in straight lines—she peered at it in the darkness, trying to discern its provenance.

It seemed to be…a story? She flipped through. Nothing with this many references to wildlife would be official church business. Unless…?—no. Here was dialogue. This was definitely some sort of story. 

Shaking her head, she straightened the pile, leaving the quill on top as she’d found it. She hadn’t come here to read Seteth’s work, whatever it might be. Somehow that felt intimately intrusive in a way fucking herself on the man’s paperwork did not.

She hopped up on his desk, the cold of the wood immediately present through the delicate lace of her tights. Thinking about how it would feel to be here, just like this, with his body pressed against hers, had her hot again in no time, and she slipped her hand down the front of her shorts, finding her own sweet spot almost immediately. 

Goddess, it felt so _good_ to think about him and touch herself—living in the student dorms, this was a luxury she didn’t allow herself often. Leaning back to give herself better access, she swept her own finger into herself, feeling her own slickness and appreciating how much this man turned her on. 

It had been too, too long since she’d been satisfied by someone else in that way, and the slightness of her own hand had her almost aching for something more substantial. No matter how well she could love herself, her fingers were a sorry substitute for the real thing.

Pressing against herself, she imagined how Seteth would feel inside of her, imagined feeling herself stretched around him. She wondered if he would look at her during their lovemaking and decided Manuela was probably right, that he’d be a man who would prefer missionary. He’d probably want to look in her eyes if he was fucking her for real. She got the sense he wasn’t someone who had a lot of sex without some sort of feeling behind it.

Too bad. She’d love to see him go feral. 

Lacking as it was, the friction she was creating was enough to cause her to buck her own hips into her hand. She let herself moan softly into the quiet of the room. The carpet dampened the sound of her arousal, and she knew it would be many months before every meeting in this office wouldn’t trigger this memory in some corner of her mind. 

Using her own lubrication, she traced small circles around her clit, imagining instead it was his tongue, causing her to sigh his name into the darkness. 

The idea of him here with her, of them trying to keep quiet while the flurry of the monastery happened past in the hallway… She rubbed herself, feeling the tension build in her core at the thought: imagining footsteps, just outside the door—

Byleth sat up straight, realizing that what she was imagining was _actually happening._

Footsteps down the hallway. _Please, keep walking,_ she prayed, listening hard. When the footsteps slowed, right outside the door— _Of course—_ she wondered frantically if Sothis’s divine pulse could rewind time back long enough to get her out of the room. 

Why had she spent so much time looking at his _swords_? 

The handle twisted, encountering the lock, and the person on the other side bounced off the door, clearly expecting it to have swung open. 

It had to be Seteth. It _had_ to be. No one else would walk into this room with such conviction. Not even Claude.

She looked around, trying to decide whether she had enough time to duck under the desk as the door swung open, revealing the man himself, fumbling with his key ring. 

Byleth’s hand was still down her shorts, frozen, legs spread wide. Their eyes met. His hair was dark in the moonlight, but she could see the green of his eyes, illuminated with surprise.

“Professor.”

She nodded her head in greeting, curtly, as though they were passing each other in the hallway. She tried to pretend she couldn’t feel the heat of her own arousal on her fingertips as she looked at the man she’d just been imagining as she’d masturbated, now framed dramatically by the doorway.

His face was strange, and for a moment, he was silent. He was dressed in his full regalia, even at half-past midnight, and Byleth wondered if this man ever truly relaxed.

As she considered whether there was a graceful way to extract her hand from her own clothing, Seteth stepped further into the room, closing the door behind him.

“Professor.” He shook his head. “I seem to recall a recent conversation in which I reminded you that you were responsible for your students’ moral instruction.” 

“Ah…yes.”

“So, pray tell, why have I found you in such a…state inside of my locked office?”

“Well…” Byleth met his eyes, and Manuela’s dare seemed lame even in head. Telling him about the students’ challenge seemed even lamer.

Seteth sighed when she didn’t continue. “Professor, you have truly been a thorn in my side since the day you arrived at the monastery.”

Byleth flushed. It’s not as though she didn’t know it—he was so _blunt_ about all of the different ways he found her annoying and unacceptable—but the last thing she’d expected when she’d left her room this evening was to be subjected to one of Seteth’s lectures with her hand down her own shorts.

“Still, even with the litany of crises that your presence here has catalyzed, _never_ in a thousand years could I possibly have imagined finding you in such a manner, on my own _desk_ , no less, and…I must admit I am quite at a loss as to how to handle this latest infraction of academy norms, and frankly, common decency.” 

Byleth didn’t know what to say. She felt very much at his mercy—and still, very much turned on. It was definitely addling her brain. 

“But as you have delivered yourself to me so _willingly_ , I am afraid I have no other choice.” He turned, locking the door once again. Byleth felt the click of the lock in her core. “I cannot let you leave until I have been…compensated. For my troubles.” 

Byleth felt her brows raise. “Compensated?” 

“Yes.” He stepped closer to her, eyes wide and taking her in. “You have been plaguing me, during waking hours—and outside of them—for months now.” He reached out, running a finger along her skin above her bustline, and the tension of his touch deliciously amplified her arousal.

“Ah—Seteth…”

“Mmm, do you like that?” He repeated the gesture before leaning in, pressing his lips to her neck, close enough that she could smell the scent of him. The sensation traveled down her arm, tingling, and looped itself into her arousal, as his hand found the bare skin of her abdomen. “I must admit that you are quite…the spectacle.”

She squirmed, her hand trapped between their bodies and the fabric of her shorts, and Seteth pushed the plane of his hip close, creating friction between them by pinning her hand against her sex.

She couldn’t help but grind against him, the sensation intensified by his proximity. Dimly, in a corner of her mind, she realized that this was not how an initial encounter with this man would have played out in her head given a million years to imagine it.

Bending down, he pressed a kiss into her neck where it met her shoulder, sweeping her hair out of the way and using it as leverage to expose the bend of her neck, marking her with his mouth where her collar would normally lay. 

She sighed as the pressure of their bodies together translated into pleasure, and she rutted against him again, almost involuntarily seeking release. 

He stepped back, leaving space between them.

Byleth huffed her consternation. In all her fantasies she’d not anticipated how fucking hot this would be, being caught and now…punished? by him, even as she flushed with embarrassment.

Seteth leaned back, crossing his arms. “Please—continue.”

“What?”

“Surely you are able to hear me in this quiet office, Byleth. After all, it _is_ just the two of us.” He smirked at his own little joke. He gestured at her. “Continue.”

Byleth flushed clear up to her ears. She knew that she didn’t have to play this game with him, that a quick roll to her left would put her in reach of the sword rack; she was confident she could outfight him, especially if he was unarmed.

But she was halfway to an orgasm already and now incandescently turned on, with the man himself watching her expectantly with his near-translucent green eyes. 

Slowly, almost not believing herself, she made eye contact with him, touching herself as he watched, allowing her face to telegraph her pleasure.

“Yes, Byleth. Just like that.”

She couldn’t help the low moan that slipped through her lips as he watched her, both of them still fully clothed. She made a small circle around her clit, and the intensity caused her to shudder. She watched him as he witnessed her touching herself, and she could see his breath begin to shallow out as he too felt the impact of being here together like this.

She couldn’t help but breathe his name into the dark air of the office once again, almost an entreaty. She could see his erection tenting his white pants, a vulgar display of his physical need at odds with the stoic ritualism of his uniform. 

Byleth felt her own cunt pulse around her hand. _Yes, Seteth. Fuck me._ She threw her head back, imagining it while she touched herself, letting him take her in. The sex-addled part of her brain urged her to undress, to bear herself to him.

She was going to fuck Rhea’s advisor, in his office. She was going to make Seteth come undone.

If she continued thinking like this much longer, she was going to—

“Oh, not yet, Byleth.” Seteth took a step closer to her, drawing her hand out of her shorts. “Not yet.”

She couldn’t help the sound that slipped from her throat as she felt her release ebb away, retreating once again into the acute tension of desire. 

Holding her wrist in one hand, and pressing her throbbing cunt with his other, he leaned in to kiss her with a ferocity that she would not have imagined came readily to this man.

His face was rough with a day’s worth of stubble, and the kiss was punishing—her lips were raw and she whined into his mouth as he kissed her, pushing her hips up and into him, wanting more, wanting _friction_. 

He broke the kiss, and releasing her wrist, he kneeled in front of her, pushing her legs apart to gain access to the core of her. While she watched, he moved aside the fabric of her shorts and traced his tongue up the middle of her sex, keeping his eyes locked on her face. 

She shuddered. The pleasure was intense, and Byleth keened, curling over and fisting her hands in the man’s hair as he pulled back to lick the length of her once again, maintaining eye contact the whole time. 

Byleth closed her eyes against the pleasure, and Seteth pulled back. “Oh no, Byleth. I need you to watch me. Open your eyes.”

She forced her eyes open against the pleasure, and met his gaze once again. His mouth was wet with her, and she knew he could see the effect of his ministrations on her own flushed face. Once she’d recentered, he bowed his head between her legs and began again, almost worshipful. 

This time, she kept her eyes locked on his as he took the bud of her clit into his mouth and sucked. Watching Seteth eat her out, watching him as he pleasured her—it was utterly scandalous, and it was blowing her mind.

The sensation was heavenly, and Byleth struggled against it, forcing herself to keep her eyes open, forcing herself to watch him suck her off. She was already so, so close. 

He pulled back, sensing her edge approaching. “Oh, Byleth. Not yet. Not until I say.” Seteth smiled, and the expression was positively wicked. “I want you to feel the same frustration you’ve caused me these last six months.”

Byleth huffed a breathy laugh.

“So you don’t get to come until I say so.” He ran a finger up the crease between her legs, circling her clit as she had done herself just moments before. “Agreed?”

Byleth nodded, careful to keep her eyes trained on his. 

“Lovely.” 

He pressed a kiss into the bare skin of her inner thigh before returning to her center, tracing her with his tongue, using her own slickness to slip two fingers into her, the friction _so_ welcome. 

“Oh, Seteth—”

Their eyes locked; he watched her greedily. “Not yet, Byleth—” He pulled his fingers out of her with a lewd sound and slowly, patiently, rhythmically pushed them in while pressing the flat of his tongue against her most sensitive spot.

She trembled.

It was enough to keep the tension of her arousal, but not enough friction to come, and she moaned her frustration into the office, low. She tried not to thrust wildly against his hand.

She kept her eyes trained on his face, certain she looked wrecked, not daring to look away. She was so close, and straining against her own body now. “Please…please—”

“Shhh. I’ll take care of you.” He slid his hand out once again, repeating the move; she was almost wild from it. Her body rocked involuntarily, trying to chase the sensation, but he pulled back, forcing her to accept his pacing. 

“Oh, Seteth, _please_ —” 

She had never, ever been so ready to come. She heard herself begging, working to hold back her orgasm as he worked her, watching him the entire time. 

“Not yet, Byleth, not yet—” 

“I—I can’t…”

With his thumb on her clit now, he slid his fingers into her once again and she felt her core contract around him—she’d never felt so good in her _life_ —her restraint was in tatters; she was going to come with or without Seteth’s permission, gritting out, “Please, please can I, can I come—”

“Not quite yet, Professor,” he replied, his voice light and conversational, as if he were remarking on the weather, or the status of a dish. Byleth couldn’t fathom how he was so put together right now when she felt so completely unraveled.

She whined into the room, a sound so desperate it could have come from an animal. She’d never heard her own voice like that before, but then again, she’d never felt the heat of own insistent arousal pulsing in her fingertips before, either. The fire contracted and she fought against it, keening—

Seteth smiled. “Okay, Byleth, okay. Let go.” 

His fingers curled up into her, pressing, pressing, pressing, and with a pulse of pleasure that started in her clit and flooded into her stomach, she came, curling up against his shoulder, crushing against him as he rocked her through the contractions.

“There you go,” he said, relentlessly stroking her through her release. “There you go. Good girl.”

She felt her cunt throb around his hand, feeling utterly depraved. Unable to support herself, she leaned into him, and his other arm reached up to steady her as she panted into the fabric of his shoulder.

Even when she’d shuddered and sighed, unclenching and pulling back enough to take in his reaction to her, he didn’t relent, pushing through her sensitivity with his hand until she could feel the heat building for another round.

She laughed, breathily. “Again?”

“Until I say so.” He laughed. “Are you ready for me?”

Her belly clenched again. She could tell he was giving her a choice here—she got to choose whether he fucked her here against his desk—and she reached up, pulling him towards her by the fabric of his jacket. 

She kissed him, pulling him into her and wrapping her legs around him. Breaking away, she pulled back far enough to look at his face as she told him, “Yes. Fuck me. Please.” 

His eyes darkened. She didn’t need to tell him twice; he shifted back, hefting her off the desk. As soon as her feet were on the ground, he spun her around, guiding her down so that she was braced over the top of his desk. 

He deliberately placed her hands on the wood of his desktop, about shoulder width apart. “Keep your hands on the surface of the desk.”

She looked over her shoulder to watch him—he was working his pants open. Part of her really wanted to get a good look at his cock before it was inside of her. She wondered if his pubic hair was also green. “And what if I don’t?” He reached over, pushing her head forward, toward the window.

“The consequence will not be to your liking, I promise you. Eyes ahead.”

She heard the rattle of his belt as he unfastened it, and a moment later, she felt his hands around her waist. He slipped his fingers into her waistband and slid her shorts and tights down her legs, leaving her bared to him, ass up in the center of his office. 

She had to work very hard to keep her eyes trained on the window in front of her. She felt his hands on the back of her thighs, his touch firm and appreciative. 

The anticipation was _killing_ her. She could feel her heartbeat in her cunt, the juxtaposition of heat and cool air almost in itself almost arousing.

She was exposed to him but she couldn’t see him, and after the intense eye contact he’d forced her to maintain, it felt a little bit like being blindfolded. He ran a finger up her sex once again, making a sound of appreciation. She rocked back into his hand, already very much aroused—being watched like this made every sensation that much more intense—and now she allowed herself to close her eyes against it. 

“You look good like this, Byleth,” he said. “I like it when you follow my instructions.” 

“I like it when your instructions mean I get laid,” she responded, laughing.

“Mmm. I bet you do.”

She could feel him behind her, even if she couldn’t see him, and she jumped in spite of herself when he replaced his finger with the tip of his cock, running it up and down her center. 

The feeling of his hot dick on her sensitive skin was heavenly, and she leaned backward, trying to encourage him to penetrate her. 

Instead, he took his time, using himself to rub her while she squirmed. 

“Seteth—” 

“Yes?”

“Are you going to, um…”

“Going to do what, Byleth?”

“Going to fuck me?”

“Oh yes. When I’m ready. But right now, I’m quite enjoying you like this.”

She sighed in frustration—feeling the heat of his erection without it filling her left her feeling empty, but there was a sense of nervous anticipation as well, and the feeling continued to build along with her arousal as he continued to use his cock to stimulate her clit. 

She moaned, grinding back towards him, using her hips to work herself against him, allowing herself to chase the sensation. 

He pulled back, leaving her wanting. She felt his hands on her hips, pulling her apart before pushing himself into her in one motion, filling her with his cock and almost cresting her off the edge into another release. 

Byleth gasped. She didn’t know if it was the position or the anticipation, but he felt huge inside of her, larger than anyone she’d been with before, and she panted as her body adjusted to the sensation of being filled by him before he started to move. 

His pace was punishing, and now she could tell he too was losing control, the fact that he was now thrusting wildly behind her some sort of gratification—that even Seteth had a breaking point and it was her that had propelled him to the edge of his own ability to control himself.

It was exhilarating.

He plunged into her, grinding himself inside of her, and she could feel his thighs flush against her backside. She pressed back against him, rolling her hips to create the friction she’d been craving—finally, _finally_ —causing him to grab her hips even tighter in response, pulling them even closer together. “Fuck, ah, _fuck_ —” He panted. “Fuck, you feel good. _Goddess_ , Byleth. You feel so fucking good.” 

He found purchase around her hips and ground into her, setting a punishing pace, especially in contrast to his incredible restraint before. He thrust again and again, and she could hear the rattle of the inkwell on the desk next to her as he fucked her halfway into oblivion—so much for her earlier imaginations about his tender lovemaking. 

She’d never been fucked so hard in her life. It was a revelation.

She felt his hand leave her hip just a second before he delivered a stinging blow to her ass—she felt the jiggle of her flesh before she felt the burn, and the pain of his open-handed strike melded with the feeling growing inside of her and almost pushed her over the edge. 

“What was _that_ for!?”

“Six months of saucy backtalk, Byleth.”

_Fair enough._

He pulled back again, smacking her exactly in the same place, and she keened. “Oh you like that, do you?” he asked. 

She wouldn’t admit it. It was too debasing.

“That was for all the nights I couldn’t get my work done because I was thinking about fucking you, just like I am now. Your choice of clothing is _incredibly_ distracting, Byleth. And entirely inappropriate for your position.” 

A third time. She felt the blossom of heat over her skin and she thrust back into him, flexing her hips and drawing him deep into her. 

“And that was because you like it, you minx.” 

She had to admit he was right. She did like it. Fuck—she loved it, and she would beg for it again if she had to.

She was so, so close—the sting of his hand mixing with the pleasure and the nerves, the sense of release, of finally, finally getting fucked by this man and having it be _nothing_ like anything she would have imagined…

“Oh, Seteth, I’m—can I, can I come?” 

He leaned in close to her, and she could feel his hair brush her shoulder before she felt his lips press against the skin of her back. “Yes, yes. Come—come for me. Come for me, Byleth.” 

She pushed back a final time and ground her cunt against him, letting the rhythm he set drive her closer and closer, her body flexing against him without her direction, her own muscles working her against his dick to bring her to release. 

With a flush and a shudder, she broke, crying his name. The flush of pleasure and release was raw and powerful, as he pushed into her once, twice, three times, through the flutter of her clenching walls and finished himself, biting into her shoulder to muffle his response to his own orgasm. 

He sighed against her, and she felt the weight of his forehead against her shoulder blade as his body contracted in response to his orgasm.

Spent, they rocked together through the aftershock, his initial bite softening into several small kisses, tender after the intensity of everything before. They remained for a moment, motionless, breathing together, and then Byleth’s arms began to shake from supporting both of their weight. 

Seteth pulled back, shifting her back with him, and as she stood up, he slid out. She reached down to pull up her shorts, covering her nakedness. 

She turned around to face him—he’d already tucked his cock into his undershorts, and part of her was disappointed that she’d not been able to see any more of this man than she did during the average faculty meeting, even after he’d fucked her near senseless.

He cleared his throat, his manner subdued and more similar to what she’d learned to expect from him. “I hope you learned something about trespassing tonight, Professor.”

Byleth tilted her head. “I suppose I did. Not necessarily the lesson I’d expected, though,” she responded, deadpan.

“Excellent. I would not want my efforts to go unrewarded.” He studied her face, and then asked, “Shall we continue our…lessons tomorrow, then?”

Byleth blinked, unbelieving. “You want a reprise?” 

“Indeed. That is, if you are…amenable.” 

She already felt a little weak in the knees at the thought of it. “I’ll consider it.”

He nodded. “Splendid. Well, goodnight, Professor. See that you don’t sneak into any other unassuming offices this evening. You might not get such a…warm welcome elsewhere.” 

“I’ll go straight to bed, don’t worry.” She huffed a laugh. Besides, she had to deal with the mess that was currently dripping down her shorts, and she’d have to take herbs before bed unless they both wanted to risk even more of a surprise nine months from now.

“See that you do.” He was halfway to the door when he turned. “Ah yes, I had forgotten why I’d come here to begin with.” 

Reaching past her, he grabbed the stack of papers that she’d inspected earlier that evening. “My book.” He smiled, and with his free hand, he cupped her face and kissed her, softly this time. “Thank you, Byleth. With all sincerity, this was an unexpected and…enjoyable interlude for me.” 

“For me, too. I would have snuck in here a lot sooner if I knew this would have come of it.”

“I’d have welcomed it. You’re a beautiful woman, Byleth, and delightfully spirited, even if you make my job quite impossible.”

Byleth blushed with pleasure at the praise. Turned out Rhea’s advisor was full of surprises himself. “You’re not so bad yourself. Goodnight, Seteth.”

“Goodnight.” He unlocked the door and let himself into the hallway, leaving her alone in his office once again.

Byleth laughed to herself in the quiet of his office, giving him a moment to clear the area before slipping out into the hallway as well. 

As she softly closed the door behind her, she realized she was on the hook for an entire bottle of whiskey. 

Even if she told her friend the truth about what had happened here tonight, Manuela would never, _ever_ believe her.

***

**Author's Note:**

> thanks for reading! 
> 
> (and for the record, i'm definitely here for top byleth too. but what is fire emblem for except for exploring all the different permutations of every little thing...right?)


End file.
